Field of the Invention
Aspects of the present invention generally relate to an electronic device which operates on a chargeable battery and a method of controlling the electronic device.
Description of the Related Art
An electronic device which operates on a chargeable battery places importance on the safety of the battery. For example, before starting charging the battery, the electronic device takes safety measures such as authenticating the battery.
When charging the battery in a fully discharged state while an authentication circuit on the battery side does not function, the electronic device cannot activate even its internal circuit because of low voltage. In this case, the electronic device uses an external power source to charge the battery to a level at which the device can activate the internal circuit, thereby making the external power source activate the internal circuit to perform authentication. Japanese Patent Laid-Open No. 2009-273219 discloses a technique of performing authentication using an internal circuit operating on an external power source when an authentication circuit on the battery side is made to function by preliminary charging.
When, however, a battery is authenticated using power supplied from an unidentified external power source, the authentication of the battery cannot be sometimes normally completed depending on the power supply capability of the external power source and responsiveness to the variation in load of the external power source.